To operate properly, the headlights of an automobile must be adjusted with respect to the vehicle body so as to be directed toward the road ahead. Presently, it is the practice to adjust the headlight orientation at the time the headlight is installed, with no further adjustment undertaken unless the original adjustment is either lost, or determined by the vehicle user to be deficient.
With the advent of miniaturized electric motors and the computer chip, it has become possible to motorize the aiming of a headlight of an automobile so that the aim of the beam is continuously adjusted as the vehicle is being driven. For example, a heavy load in the trunk of the vehicle will cause the rear springs of the vehicle to become compressed, such that the headlight beams will become elevated and directed into the eyes of oncoming drivers. By providing sensors in the shock absorbers and motorized controls for aiming the headlight beams, the beams can be adjusted downwardly to compensate for the changes in the vehicle orientation. Similarly, motorized controls for the headlights can turn one or both of the headlight beams to one side when sensors in the steering mechanism of the vehicle determine that the vehicle is undertaking a turn. It is anticipated that in the not too distant future, government safety regulations will require vehicle manufacturers to provide motorized controls for headlights.
The motorizing of controls for headlights will not eliminate the need, however, for adjusting the aim of the headlights with respect to the vehicle body when the vehicle is in a steady state condition. For example, if the headlights of a vehicle are not aimed at the proper elevation while the vehicle is in the steady state condition, a microprocessor responding to detectors in the shock absorbers will be unable to properly adjust the beam in response to a load in the trunk. Similarly, motorized controls for the horizontal adjustment of the headlights as the vehicle undertakes a turn cannot be properly undertaken where the headlight beam is directed off road while the vehicle is traveling in a straight line. The motorizing of the controls of a headlight beam require that the headlight position be manually adjustable with respect to the vehicle frame so as to be properly aimed in the steady state condition, where the steady state condition is defined as the vehicle being substantially unloaded, resting on a level surface with the beams directed to illuminate the roadway immediately ahead.
It has become customary to mount the body of a headlight to a vehicle frame by providing three mounting points positioned around the circumference of the headlight body. To manually adjust the aim of a headlight beam, adjustment screws are provided at least two of the three mounting locations of a headlight body. Where only two of the mounting locations are adjustable, the third mounting location typically consists of a ball joint or the like such that one of the two adjustable locations will change the vertical elevation of the beam and the second of the adjustable locations will change the horizontal orientation of the beam.
Prior efforts to motorize the controls for aiming a headlight require that the headlight body be mounted in a first frame pivotable about a first axis, for example a horizontal axis, and the first frame mounted in a second frame pivotable about a second axis, for example a vertical axis. A first motor then adjusts the first frame with respect to the second frame and a second motor adjusts the second frame with respect to the vehicle body. Such efforts not only require the precision manufacture and assembly of several moving parts but also require a considerable enlargement of the space allocation required for the mounting of the headlight. It would be desirable to provide a more efficient mounting of a motorized headlight so as to reduce the amount of space needed to undertake motorized controls and still provide for the manual adjustment of a beam under steady state conditions.